const fs = require('fs');
const path = require('path');

class CsvExport {
  /**
   * @param {string} logDir - Directory where log files will be saved
   * @param {string[]} headers - CSV header row  
   */
  constructor(filePath, headers = ['ID-Nummer', 'Datum (TT.MM.JJJ)', 'Tracking-Nr.','Versandinfos','Beilegeretoure']) {
    this.filePath = filePath;
    this.headers = headers;    
    

    if (!fs.existsSync(path.dirname(filePath))) {
      fs.mkdirSync(path.dirname(filePath), { recursive: true });
    } else if (fs.existsSync(filePath)){
      fs.unlinkSync(filePath)
    }
  }

  /**
   * Writes a new log entry to today's CSV file

   */
  add(data) {
   
   

    this.ensureFileWithHeaders( this.filePath );

    const row = [data.id, data.date, data.trackingNr, data.infos, data.returnTrackingNr]
      .map(this.escapeCsv)
      .join(';') + '\n';

    fs.appendFileSync( this.filePath , row, (err) => {
      if (err) {
        console.error('Failed to write to csv file:', err);
      }
    });
  }

 

  /**
   * Ensures headers are written if file doesn't exist
   */
  ensureFileWithHeaders(filePath) {
    if (!fs.existsSync(filePath)) {
      const headerRow = this.headers.join(';') + '\n';
      fs.writeFileSync(filePath, headerRow);
    }
  }

  /**
   * Escapes a value for safe CSV output
   */
  escapeCsv(value) {
    if (value == null) return '';
    const str = String(value);
    return /[",\n]/.test(str) ? `"${str.replace(/"/g, '""')}"` : str;
  }

}

module.exports = CsvExport;